Mobile devices such as laptop computers, tablet computers, smartphones, digital book readers, and many such devices utilize various modes of wireless communication reaching the internet. Wi-Fi network from a wireless access point, and wireless broadband such as 3G or 4G data service over a wireless service provider's network are the two most commonly used wireless methods for connecting to the internet from a mobile device.
Many places offer free Wi-Fi access to mobile devices when they are within range of a Wi-Fi access point device. For example, certain coffee shops offer free use of their Wi-Fi network to their patrons. Unintentionally, persons who are not patrons, and not even present in the place of business, can also detect the free Wi-Fi network and use the free Wi-Fi services.
Some entities that provide free Wi-Fi access also employ some method of controlling that access. For example, the coffee shop may require a password that can only be obtained on a sales receipt upon purchase of some product. As another example, some public places, such as libraries, limit the use of free Wi-Fi access to preset durations. Some other entities configure their access points to allow only a certain number of devices to connect at any given time.